is by no means superfluous, for the word is acquiring a more and more, extended use and a looser and looser meaning, and will soon come to designate any sort of influence whatever, just as in English, where 'to suggest' and 'suggestion' correspond to our nahelegen and Anregung. But there has been no explanation of the nature of suggestion, that is, of the conditions under which influence without adequate logical foundation takes place. I should not avoid the task of supporting this statement by an analysis of the literature of the last thirty years, if I were not aware that an exhaustive inquiry is being undertaken close at hand which has in view the fulfilment of this very task.
Instead of this I shall make an attempt at using the concept of libido for the purpose of throwing light upon Group Psychology, a concept which has done us such good service in the study of psycho-neuroses.
Libido is an expression taken from the theory of the emotions. We call by that name the energy (regarded as a quantitative magnitude, though not at present actually mensurable) of those instincts which have to do with all that may be comprised under the word 'love'. The nucleus of what we mean by love naturally consists (and this is what is commonly called love, and what the poets sing of) in sexual love with sexual union as its aim. But we
